Influenza - Known epidemics and pandemics - overview

Influenza (or as it is commonly known, the flu or the grippe) is a contagious disease of the upper airways and the lungs, caused by an RNA virus of the orthomyxoviridae family. It rapidly spreads around the world in seasonal epidemics, imposing considerable economic burden, in the form of health care costs and lost productivity. Three influenza pandemics in the 20th century, each following a major genetic ...

Including:

• Influenza - Types
• Influenza - Genetics
• Influenza - History
• Influenza - Known epidemics and pandemics - overview
• Influenza - Symptoms
• Influenza - Variability
• Influenza - Flu season
• Influenza - Prevention
• Influenza - Treatment
• Influenza - Avian influenza
• Influenza - Sources

Read more here: » Influenza: Encyclopedia - Influenza

There are three genera of the virus, identified by antigenic differences in their nucleoprotein and matrix protein: Influenza A viruses are known to infect humans, other mammals and birds (see also avian influenza) Influenza B viruses are known to infect humans and seals Influenza C viruses are known to infect humans and pigs [1]. The A type of influenza virus is the type most likely to cause epidemics and pandemics. This is because the influenza A virus can undergo antigenic shift and present a n ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Influenza - Types

Influenza reaches peak prevalence in winter, and because the Northern and Southern Hemisphere have winter at different times of the year, there are actually two flu seasons each year. Therefore, the World Health Organization makes two vaccine formulations every year; one for the Northern, and one for the Southern Hemisphere. While most influenza outbreaks in the Northern Hemisphere tend to peak in January or February, not all do. For example, the influenza pandemic of 1918 and 1919 reached peak virulence during late spring and summer ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Influenza - Flu season

The virus attacks the respiratory tract, is transmitted from person to person by saliva droplets expelled by coughing, and causes the following symptoms: Fever Headache Fatigue/Sore joints (can be extreme) Dry cough Sore throat Nasal congestion Sneezing Irritated eyes Body aches Extreme coldness Influenza's effects are much more severe, and last longer than those of the "cold". Recovery takes about one to two weeks. Influenza can be deadly, especially for the weak, old or chronically ill. Some flu pan ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Influenza - Symptoms

Antiviral treatments that have proven effective in influenza are amantadine, rimantadine, zanamivir, oseltamivir and ribavirin. As most of these substances are expensive, various healthcare organisations and insurers only support their use where this would make a significant difference, e.g. in the elderly. Worryingly, investigators at the CDC in Atlanta found high rates of resistance to adamantane derivatives (amantadine, rimantadine) in the H3N2 strain of influenza A: China 74%, Hong Kong (70%), Taiwan (23%), South Korea (15%) (Brig ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Influenza - Treatment

Genetic reassortment ("mixing") of a human flu virus with the current H5N1 avian influenza has been identified as the most likely source of the next pandemic. The natural host for influenza virus is aquatic birds. Pandemic influenza often occurs when an avian-adapted virus infects a porcine host, which can be infected by human and avian varieties of influenza A virus. The virus may then recombine within the pig, to ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Influenza - Avian influenza

Influenza A viruses contain their genome in eight separate linear segments of negative-sense RNA, which code for ten proteins (eleven for type A if including the novel PB1-F1 protein) [2]. Each segment contains a single gene, but some can be read twice at different starting points to create two distinct proteins. The segmented nature of the genome also allows for the exchange of entire genes between different viral strains when they cohabitate the same cell. The 8 genes are: HA gene encoding hemagglutinin which produces about 50 ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Genetics

There were several serious outbreaks of influenza in the 20th century. The most famous (and the most lethal) was the so-called Spanish Flu pandemic (type A influenza, H1N1 strain), which lasted from 1918 to 1919, and is believed to have killed more people in total than World War I. While the war casualties accumulated over several years, the pandemic took most of its toll over a period of weeks. Lesser flu epidemics included the 1957 Asian Flu (type A, H2N2 strain) and the 1968 Hong Kong Flu (type A, H3N ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Influenza - History

Influenza A viruses contain their genome in eight separate linear segments of negative-sense RNA, which code for ten proteins (eleven for type A if including the novel PB1-F1 protein) [2]. Each segment contains a single gene, but some can be read twice at different starting points to create two distinct proteins. The segmented nature of the genome also allows for the exchange of entire genes between different viral strains when they cohabitate the same cell. The 8 genes are: HA gene encoding hemagglutinin which produces about 50 ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Influenza - Genetics

Influenza reaches peak prevalence in winter, and because the Northern and Southern Hemisphere have winter at different times of the year, there are actually two flu seasons each year. Therefore, the World Health Organization makes two vaccine formulations every year; one for the Northern, and one for the Southern Hemisphere. While most influenza outbreaks in the Northern Hemisphere tend to peak in January or February, not all do. For example, the influenza pandemic of 1918 and 1919 reached peak virulence during late spring and summer ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Flu season

The virus attacks the respiratory tract, is transmitted from person to person by saliva droplets expelled by coughing, and causes the following symptoms: Fever Headache Fatigue/Sore joints (can be extreme) Dry cough Sore throat Nasal congestion Sneezing Irritated eyes Body aches Extreme coldness Influenza's effects are much more severe, and last longer than those of the "cold". Recovery takes about one to two weeks. Influenza can be deadly, especially for the weak, old or chronically ill. Some flu pan ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Symptoms

Antiviral treatments that have proven effective in influenza are amantadine, rimantadine, zanamivir, oseltamivir and ribavirin. As most of these substances are expensive, various healthcare organisations and insurers only support their use where this would make a significant difference, e.g. in the elderly. Worryingly, investigators at the CDC in Atlanta found high rates of resistance to adamantane derivatives (amantadine, rimantadine) in the H3N2 strain of influenza A: China 74%, Hong Kong (70%), Taiwan (23%), South Korea (15%) (Brig ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Treatment

Genetic reassortment ("mixing") of a human flu virus with the current H5N1 avian influenza has been identified as the most likely source of the next pandemic. The natural host for influenza virus is aquatic birds. Pandemic influenza often occurs when an avian-adapted virus infects a porcine host, which can be infected by human and avian varieties of influenza A virus. The virus may then recombine within the pig, to ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Avian influenza

There are three genera of the virus, identified by antigenic differences in their nucleoprotein and matrix protein: Influenza A viruses are known to infect humans, other mammals and birds (see also avian influenza) Influenza B viruses are known to infect humans and seals Influenza C viruses are known to infect humans and pigs [1]. The A type of influenza virus is the type most likely to cause epidemics and pandemics. This is because the influenza A virus can undergo antigenic shift and present a n ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - Types

There were several serious outbreaks of influenza in the 20th century. The most famous (and the most lethal) was the so-called Spanish Flu pandemic (type A influenza, H1N1 strain), which lasted from 1918 to 1919, and is believed to have killed more people in total than World War I. While the war casualties accumulated over several years, the pandemic took most of its toll over a period of weeks. Lesser flu epidemics included the 1957 Asian Flu (type A, H2N2 strain) and the 1968 Hong Kong Flu (type A, H3N ...

See also:

Influenza, Influenza - Types, Influenza - Genetics, Influenza - History, Influenza - Known epidemics and pandemics - overview, Influenza - Symptoms, Influenza - Variability, Influenza - Flu season, Influenza - Prevention, Influenza - Treatment, Influenza - Avian influenza, Influenza - Sources

Read more here: » Influenza: Encyclopedia II - History